diff --git a/hw/unittest/cache/Makefile b/hw/unittest/cache/Makefile
index e3737c3c..0d5da094 100644
--- a/hw/unittest/cache/Makefile
+++ b/hw/unittest/cache/Makefile
@@ -33,7 +33,7 @@ VL_FLAGS = --exe
 VL_FLAGS += --language 1800-2009 --assert -Wall -Wpedantic
 VL_FLAGS += -Wno-DECLFILENAME -Wno-REDEFMACRO
 VL_FLAGS += --x-initial unique --x-assign unique
-VL_FLAGS += -DSIMULATION
+VL_FLAGS += -DSIMULATION -DSV_DPI
 VL_FLAGS += $(CONFIGS)
 VL_FLAGS += $(PARAMS)
 VL_FLAGS += $(RTL_INCLUDE)
diff --git a/hw/unittest/generic_queue/Makefile b/hw/unittest/generic_queue/Makefile
index 9ec4baa1..c25bc006 100644
--- a/hw/unittest/generic_queue/Makefile
+++ b/hw/unittest/generic_queue/Makefile
@@ -27,7 +27,7 @@ VL_FLAGS = --exe
 VL_FLAGS += --language 1800-2009 --assert -Wall -Wpedantic
 VL_FLAGS += -Wno-DECLFILENAME -Wno-REDEFMACRO
 VL_FLAGS += --x-initial unique --x-assign unique
-VL_FLAGS += -DSIMULATION
+VL_FLAGS += -DSIMULATION -DSV_DPI
 VL_FLAGS += $(CONFIGS)
 VL_FLAGS += $(PARAMS)
 VL_FLAGS += $(RTL_INCLUDE)
diff --git a/hw/unittest/mem_streamer/Makefile b/hw/unittest/mem_streamer/Makefile
index 9ff5e81c..aa4b517a 100644
--- a/hw/unittest/mem_streamer/Makefile
+++ b/hw/unittest/mem_streamer/Makefile
@@ -27,7 +27,7 @@ VL_FLAGS = --exe
 VL_FLAGS += --language 1800-2009 --assert -Wall -Wpedantic
 VL_FLAGS += -Wno-DECLFILENAME -Wno-REDEFMACRO
 VL_FLAGS += --x-initial unique --x-assign unique
-VL_FLAGS += -DSIMULATION
+VL_FLAGS += -DSIMULATION -DSV_DPI
 VL_FLAGS += $(CONFIGS)
 VL_FLAGS += $(PARAMS)
 VL_FLAGS += $(RTL_INCLUDE)
diff --git a/hw/unittest/top_modules/Makefile b/hw/unittest/top_modules/Makefile
index 7445381e..72a403c5 100644
--- a/hw/unittest/top_modules/Makefile
+++ b/hw/unittest/top_modules/Makefile
@@ -25,7 +25,7 @@ VL_FLAGS = --exe
 VL_FLAGS += --language 1800-2009 --assert -Wall -Wpedantic
 VL_FLAGS += -Wno-DECLFILENAME -Wno-REDEFMACRO
 VL_FLAGS += --x-initial unique --x-assign unique
-VL_FLAGS += -DSIMULATION
+VL_FLAGS += -DSIMULATION -DSV_DPI
 VL_FLAGS += $(CONFIGS)
 VL_FLAGS += $(PARAMS)
 VL_FLAGS += $(RTL_INCLUDE)